Re: Topband: Fwd: Echo on 160m yesterday morning

[Arthur Delibert]

Thanks for these references on magnetospheric ducting.  Looks like as good an 
explanation as any I've seen (and better than most).


Art Delibert, KB3FJO



From: Topband  on behalf of Andy Cook 

Sent: Monday, February 6, 2017 7:20 AM
To: topband@contesting.com
Subject: Topband: Fwd: Echo on 160m yesterday morning

I think you'll find this was Magnetospheric Ducting. Take a look at some of the 
articles here http://la3za.blogspot.co.uk/search/label/Unusual%20Propagation 
and here http://folk.uio.no/sverre/papers/2009_MagnetoDucting-QST-LA3ZA.pdf.
LA3ZA Radio & 
Electronics
la3za.blogspot.co.uk
Radio amateur, ham radio blog

ad hi - 
folk.uio.no
folk.uio.no
There are some instrumentation prob- lems when using ham transceivers as 
"radar" sets. Transmitlreceive switching may not be fast enough, and our newer 
rigs


Delay depends on your latitude - but couple of hundred millseconds is about 
right and this is a peak time of year for the effect.
I've heard this quite frequently on 80m around mid local-evening during the 
winter, and one occasion - on 3rd Feb last year - very strongly indeed. That 
night I was able to hear my echoes with just 25mW into a dipole on 80m - but 
it's often strong enough to be audible with a few watts. I've read papers which 
suggested it does also occur on 160m.
Reports of these being less strong / gone when you switch to a vertical look 
plausible as well since they apear to require vertical incidence from the 
ionosphere.
73,
Andy, G4PIQ
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Topband: Long-delay Echos

[dick.bingham]

Greetings All

Back in the late '70s I experienced some long duration echoes on 80-meters SSB. 
I had been burning the candle at both ends DXing at my pre-sunrise and late 
after dark for a few days and was falling asleep at the "mic".

I found myself getting teed-off by someone CQing on the freq I was using only 
to discover it was ME - my speech was delayed sufficiently to hear several 
complete words at the end of each transmission. Too bad I was too tired to 
properly document this event.

This took place at a QTH 100-miles north of Frisco.

73 Dick w7wkr/7 at CN97uj



-
 


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Re: Topband: Echo on 160m yesterday morning

[Mike Waters]

This is interesting.

I recall a discussion here about very long LDEs awhile back. IIRC, it was
suggested that perhaps the magnetosphere and the Van Allen belts might be
involved, rather than the much closer ionosphere.

I heard a double echo on 75m last year. I heard his direct signal which was
followed by two echoes. All this was milliseconds apart.
The station was in NW Ohio and I'm in SW Missouri.

73, Mike
www.w0btu.com
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Re: Topband: Echo on 160m yesterday morning

[Brian Pease]

I experienced long delayed CW echos once on 20m, back in the 1980s 
before there was much wireless stuff.  Also, I lived in the country with 
no close neighbors.  The delay was significant because I was not using 
instant break-in, with the rig taking at least 1/4 sec to switch to 
receive.  I think it might have been longer than the delay of an around 
the world path.  Besides, I think I was using my 2 Watt QRP rig.


On 2/6/2017 12:23 PM, JC wrote:

Nowadays we have a huge amount of RF repeaters in use for several services,
like , Wi-Fi , LTE4, Data links. Microwave links, FM stations link, TV video
links.

All these systems has a receiver and a transmitter. The intermediated
frequency used can be close to few MHz depending the services. Like video.
Our HF signal can become data in these system,. A lot of this system does
not have the quality necessary, price is always a sales point, so poor
shield is very common.

  SDR technology that provide long delays, and  with very bad IP3 front end
are very common used on these system.

The long cables with not appropriate ground can become efficient antennas
for low bands, the common mode noise can get into the IF system and on the
receiver side and retransmitted on the transmitter side.

My point is that atmospheric plasma loops may not be the only answer for
250ms echo's. It is most unlike due the small power used during the event
observed. Manmade echo are more likely to explain the echo.

73's
JC
N4IS



  repeaters, Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tim
Shoppa
Sent: Sunday, February 05, 2017 4:44 PM
To: on7eh 
Cc: topBand List 
Subject: Re: Topband: Echo on 160m yesterday morning

I have heard echoes of my own signal under some circumstances too. More
often on 80M but a couple times on 160M. Often in the hour before dawn.

These echoes were also heard on other stations within a few hundred miles,
especially ones to my north.

For the 160M echoes, some stations in W1 were nearly uncopyable on my
receive antenna (K9AY) because of the echo. The echo was very similar to a
dit length and very similar in strength.

Interestingly enough, if I went to listen on my transmit antenna (Vertical),
the echo completely went away.

Tim N3QE

On Sun, Feb 5, 2017 at 4:32 AM, on7eh  wrote:


For the first time,
I heard my echoes on topband, yesterday morning starting around 05 UTC.
They lasted for at least 1 hour, with some OFF-periods in between.
I had to quit at 06 UTC. (still 1 hour before surise)

The echoes were loudest on the short Beverages (<60m long) heading N/S
and NE/SW and several dB lower on the NW/SE Beverage. (about 130m long).
The Tx setup is modest with Elecraft K3/100 and inv L at 15m height,
sloping down to 11m.

Only DX heard that morning was USA (typical condictions) so I wonder
what else does hearing echoes indicate?


73,
Michel, ON7EH



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Re: Topband: LDE on 160m

[Steve]

I had a friend (VE7BLF) many years ago who noted the same thing on 160m, 
with his 'night before' CW CQ's being heard 24 hours later! The signals were 
somewhat watery and not very stable...rather tortured sounding as if they 
had been to hell and back. The mystery continued for a few years but was 
never really solved ... we eventually decided that it might be coming from 
the neighbor's VCR.


Recently, VE7CNF reproduced the condition with a controlled experiment:

http://phasordesign.com/VE7CNFamateurRadio/VCRLDE/VE7CNF_VHS_Propagation.htm

I suspect that any LDE's of unusually long time spans may be a result of 
something similar.


Steve  VE7SL



New site location:

WEB - "The VE7SL Radio Notebook":  http://qsl.net/ve7sl/

VE7SL BLOG - "Homebrewing and Operating Adventures From 2200m to Nanowaves": 
http://ve7sl.blogspot.ca/ 


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Re: Topband: Echo on 160m yesterday morning

[JC]

Nowadays we have a huge amount of RF repeaters in use for several services,
like , Wi-Fi , LTE4, Data links. Microwave links, FM stations link, TV video
links. 

All these systems has a receiver and a transmitter. The intermediated
frequency used can be close to few MHz depending the services. Like video.
Our HF signal can become data in these system,. A lot of this system does
not have the quality necessary, price is always a sales point, so poor
shield is very common.

 SDR technology that provide long delays, and  with very bad IP3 front end
are very common used on these system.  

The long cables with not appropriate ground can become efficient antennas
for low bands, the common mode noise can get into the IF system and on the
receiver side and retransmitted on the transmitter side. 

My point is that atmospheric plasma loops may not be the only answer for
250ms echo's. It is most unlike due the small power used during the event
observed. Manmade echo are more likely to explain the echo.

73's
JC
N4IS



 repeaters, Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tim
Shoppa
Sent: Sunday, February 05, 2017 4:44 PM
To: on7eh 
Cc: topBand List 
Subject: Re: Topband: Echo on 160m yesterday morning

I have heard echoes of my own signal under some circumstances too. More
often on 80M but a couple times on 160M. Often in the hour before dawn.

These echoes were also heard on other stations within a few hundred miles,
especially ones to my north.

For the 160M echoes, some stations in W1 were nearly uncopyable on my
receive antenna (K9AY) because of the echo. The echo was very similar to a
dit length and very similar in strength.

Interestingly enough, if I went to listen on my transmit antenna (Vertical),
the echo completely went away.

Tim N3QE

On Sun, Feb 5, 2017 at 4:32 AM, on7eh  wrote:

> For the first time,
> I heard my echoes on topband, yesterday morning starting around 05 UTC.
> They lasted for at least 1 hour, with some OFF-periods in between.
> I had to quit at 06 UTC. (still 1 hour before surise)
>
> The echoes were loudest on the short Beverages (<60m long) heading N/S 
> and NE/SW and several dB lower on the NW/SE Beverage. (about 130m long).
> The Tx setup is modest with Elecraft K3/100 and inv L at 15m height, 
> sloping down to 11m.
>
> Only DX heard that morning was USA (typical condictions) so I wonder 
> what else does hearing echoes indicate?
>
>
> 73,
> Michel, ON7EH
>
>
>
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Re: Topband: LDE on 160m

[W7RH]

In the mid -80's while living in Seattle ,WA I experienced extremely 
strong LDE signals on 160M while in a SSB ragchew with locals on 
~1860kHz. Unfortunately I lost the tape in my move to the SW US. The 
delays were approximately 1 sec and were only heard within a radius of 
about 50 miles.



A more interesting note was posted on this reflector several years ago 
by AKI, JA5DQH of a delay of


25 hours 29 minutes! Links are here: http://w7rh.net/LDE.html and  
http://w7rh.net/audio_files/JA5DQH_LDE.mp3


de Bob, W7RH

--
W7RH DM35OS

Only two things are infinite, the universe and human stupidity, and I'm not 
sure about the former.

Albert Einstein


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Topband: Echo on 160m

[Carl Luetzelschwab]

Bruce K1FZ said: "I have noticed that there appears to be a link between
the start of an aurora and long path 160 meter openings."

Others have noted this interesting effect. The only physical tie between
the two that I'm aware of is that a spike in the K index can initially
improve the electron density valley that is above the E region peak in the
nighttime ionosphere, resulting in a better chance of ducting. This comes
from a paper by Zhang and Kamide in JGR in 2004 (they just reported their
results, but didn't tie it to amateur radio propagation - heck, they might
not even be aware of amateur radio!).

I'm not saying this is exactly what happens, just that it *may* explain the
link between the start of an aurora and long path 160 meter openings.

As for the echoes that started this thread and aurora, one respondent
wondered about the velocity of propagation of the RF slowing down due to a
back scatter mechanism. Ionosondes report virtual height (not true height)
because they assume the speed of light for the vertical incident RF. But as
the RF goes up in the ionosphere, the group velocity decreases as the index
of refraction approaches zero. If these echoes are of Earthly origin, then
the appropriate plasma frequency could decrease the group velocity and
contribute to the echo mechanism. Just speculation.

Having said all this, right now I think Andy G4PIQ's comments are most
appropriate for the echoes - unless there is some data and physical
mechanism that says otherwise. Of course this is the problem with many of
these unusual occurrences - we don't have enough relevant data with respect
to the ionosphere or whatever - just observations of an interesting
happening.

Carl K9LA
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Re: Topband: Echo on 160m yesterday morning

[K1FZ-Bruce]

 Andy,

There was a passenger on an airliner that took photographs of a very large 
Aurora at that time. .  One of the photographs was shown on TV   -ABC World 
News.

It is likely that the Aurora sparked all these events.

I have noticed that there appears to be a link between the start of an aurora 
and long path 160 meter openings.

73,  DX,

Bruce-K1FZ


 On Mon, 6 Feb 2017 14:42:58 +, Andy Cook  wrote:

I think this form of ducting takes place way above the layers of the atmosphere 
where weather happens. In my experience the magnetospheric ducting is normally 
localized in impact. If this was really happening in multiple places around the 
world at the same time on this occasion then I think that is unusual.

Andy, G4PIQ

-Original Message-
From: "K1FZ-Bruce" 
Sent: ‎06/‎02/‎2017 13:46
To: "g4...@btinternet.com" ; "Topband" 
Subject: Fwd:  Echo on 160m yesterday morning


 

Hi Andy,

Ducting takes place over a relatively small area.  Depends upon cloud layers 
and temperature zones

This event took place   ~ world wide.   Band openings between North America  to 
Asia, and Australia.

73
Bruce-k1fz
http://www.qsl.net/k1fz/beverage_antenna.html




 On Mon, 6 Feb 2017 12:20:07 + (GMT), Andy Cook  wrote:

I think you'll find this was Magnetospheric Ducting. Take a look at some of the 
articles here http://la3za.blogspot.co.uk/search/label/Unusual%20Propagation 
and here http://folk.uio.no/sverre/papers/2009_MagnetoDucting-QST-LA3ZA.pdf. 
Delay depends on your latitude - but couple of hundred millseconds is about 
right and this is a peak time of year for the effect. 
I've heard this quite frequently on 80m around mid local-evening during the 
winter, and one occasion - on 3rd Feb last year - very strongly indeed. That 
night I was able to hear my echoes with just 25mW into a dipole on 80m - but 
it's often strong enough to be audible with a few watts. I've read papers which 
suggested it does also occur on 160m.
Reports of these being less strong / gone when you switch to a vertical look 
plausible as well since they apear to require vertical incidence from the 
ionosphere.
73,
Andy, G4PIQ 
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Re: Topband: Echo on 160m yesterday morning

[Andy Cook]

I think this form of ducting takes place way above the layers of the atmosphere 
where weather happens. In my experience the magnetospheric ducting is normally 
localized in impact. If this was really happening in multiple places around the 
world at the same time on this occasion then I think that is unusual.

Andy, G4PIQ

-Original Message-
From: "K1FZ-Bruce" 
Sent: ‎06/‎02/‎2017 13:46
To: "g4...@btinternet.com" ; "Topband" 

Subject: Fwd:  Echo on 160m yesterday morning


 

Hi Andy,

Ducting takes place over a relatively small area.  Depends upon cloud layers 
and temperature zones

This event took place   ~ world wide.   Band openings between North America  to 
Asia, and Australia.

73
Bruce-k1fz
http://www.qsl.net/k1fz/beverage_antenna.html




 On Mon, 6 Feb 2017 12:20:07 + (GMT), Andy Cook  wrote:

I think you'll find this was Magnetospheric Ducting. Take a look at some of the 
articles here http://la3za.blogspot.co.uk/search/label/Unusual%20Propagation 
and here http://folk.uio.no/sverre/papers/2009_MagnetoDucting-QST-LA3ZA.pdf. 
Delay depends on your latitude - but couple of hundred millseconds is about 
right and this is a peak time of year for the effect. 
I've heard this quite frequently on 80m around mid local-evening during the 
winter, and one occasion - on 3rd Feb last year - very strongly indeed. That 
night I was able to hear my echoes with just 25mW into a dipole on 80m - but 
it's often strong enough to be audible with a few watts. I've read papers which 
suggested it does also occur on 160m.
Reports of these being less strong / gone when you switch to a vertical look 
plausible as well since they apear to require vertical incidence from the 
ionosphere.
73,
Andy, G4PIQ 
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Topband: Fwd: Echo on 160m yesterday morning

[K1FZ-Bruce]

 

Hi Andy,

Ducting takes place over a relatively small area.  Depends upon cloud layers 
and temperature zones

This event took place   ~ world wide.   Band openings between North America  to 
Asia, and Australia.

73
Bruce-k1fz
http://www.qsl.net/k1fz/beverage_antenna.html




 On Mon, 6 Feb 2017 12:20:07 + (GMT), Andy Cook  wrote:

I think you'll find this was Magnetospheric Ducting. Take a look at some of the 
articles here http://la3za.blogspot.co.uk/search/label/Unusual%20Propagation 
and here http://folk.uio.no/sverre/papers/2009_MagnetoDucting-QST-LA3ZA.pdf. 
Delay depends on your latitude - but couple of hundred millseconds is about 
right and this is a peak time of year for the effect. 
I've heard this quite frequently on 80m around mid local-evening during the 
winter, and one occasion - on 3rd Feb last year - very strongly indeed. That 
night I was able to hear my echoes with just 25mW into a dipole on 80m - but 
it's often strong enough to be audible with a few watts. I've read papers which 
suggested it does also occur on 160m.
Reports of these being less strong / gone when you switch to a vertical look 
plausible as well since they apear to require vertical incidence from the 
ionosphere.
73,
Andy, G4PIQ 
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Topband: Fwd: Echo on 160m yesterday morning

[Andy Cook]

I think you'll find this was Magnetospheric Ducting. Take a look at some of the 
articles here http://la3za.blogspot.co.uk/search/label/Unusual%20Propagation 
and here http://folk.uio.no/sverre/papers/2009_MagnetoDucting-QST-LA3ZA.pdf. 
Delay depends on your latitude - but couple of hundred millseconds is about 
right and this is a peak time of year for the effect. 
I've heard this quite frequently on 80m around mid local-evening during the 
winter, and one occasion - on 3rd Feb last year - very strongly indeed. That 
night I was able to hear my echoes with just 25mW into a dipole on 80m - but 
it's often strong enough to be audible with a few watts. I've read papers which 
suggested it does also occur on 160m.
Reports of these being less strong / gone when you switch to a vertical look 
plausible as well since they apear to require vertical incidence from the 
ionosphere.
73,
Andy, G4PIQ 
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